Temperature control

ABSTRACT

A suspended ceiling (C) comprises one or more panels (P) containing water (W) arranged so that the water is in contact with substantially all of the lower surface (10) of the panels (P).

FIELD OF THE INVENTION

The invention relates to the temperature control of areas in buildingssuch as rooms in offices, hotels, retail shops, supermarkets, hospitals,and the like. In particular the invention relates to the cooling ofrooms by transfer of heat from the air in the room by means of ceilingstructure suspended below the top surface of the room.

BACKGROUND OF THE INVENTION

It is known to suspend a ceiling structure below the top surface of theroom, the structure comprising panels incorporating pipes containing afluid medium typically water. Heat is transferred from the hot air inthe room into the pipes and extracted from the room, to keep thetemperature in the room be low a predetermined limit. This system hasseveral drawbacks.

SUMMARY OF THE INVENTION

It is one object of this invention to provide a suspended ceiling whichis more efficient and advantageous in controlling the climate of a room.

In one aspect the invention provides a building including a room havinga top surface, a ceiling suspended by hanger means below the topsurface, the ceiling comprising one or more panels containing a fluidmedium, characterised in that the fluid medium is in contact withsubstantially all of the lower surface of the panels whereby heattransfer occurs over substantially all of the lower surface.

Preferably the lower surface of the panels is in direct contact with theair of the room. As a result there is a direct transfer of heat from theair into the fluid medium.

Preferably the lower surface of the panels is contoured to increase thesurface area thereof. This may be by suitable shaping and/or the lowersurface may be covered with a paint or the like to provide a texturedfinish.

Preferably the panels include flow control means to distribute the fluidevenly therethrough from an inlet to an outlet. Preferably the inlet andthe outlet are set at opposite sides of the panel, e.g. diagonally, orin whichever way iS efficient for making connections between the panelsmaking up the ceiling.

The panels may be made of metal, or plastics, or plastics covered sheetmetal. Preferably they are moulded of polycarbonate, PVC-u, ABS, highimpact styrene or polymethylmethacrylate or any suitable plastic whichis inflammable. The mechanical strength of the material forming thepanel walls is selected so that the panels can support their own weightand that of the fluid medium without distortion. Preferably in the caseof plastics the panels are made of a material having a tensile strengthat 23° C. of about 60 MPa and a flexural strength of about 90 MPa; thesevalues will be higher where the panels are made of metal.

The panels may have one wall made of metal for strength, e.g. a plasticcoated steel sheeting. Extra layers may be present, e.g. heat insulatinglayers. A finish may be applied to the panels after moulding, e.g. apaint layer especially of a textured paint, as that will increase thesurface area and avoid zones where there is such a temperaturedifference that condensation can occur.

The panels may be moulded in such a way that there is no need to useT-bars to form a ceiling grid. Thus hook means may be present on thepanels and connected to the hanger means whereby the panels aresuspended directly from the hanger means. Also, adjacent panels may beshaped so that the lower surface thereof provides a substantiallycontinuous surface.

In one embodiment of the invention the ceiling constitutes the lowerwall of a building services duct. In such a case an inlet for fresh airmay be present in the duct and the ceiling panels of the invention arearranged to transfer heat to the incoming air from the upper surfacethereof.

Preferably the fluid medium comprises water which may contain additivessuch as dyes, anti-freeze agents, agents against bacteria and otherorganisms; and the like.

In another aspect the invention provides a method of cooling a room in abuilding, the room containing a ceiling suspended by hanger means belowthe top surface of the room, the ceiling comprising one or more panelsthrough which a fluid medium is passed characterised by contacting thefluid medium with substantially all of the lower surface of the panel.

The method preferably includes the step of locating flow control meansin the panel to distribute the fluid evenly in a path from an inlet ofthe panel to an outlet thereof.

Most preferably the fluid medium is passed under a pressure of less thanabout 1 bar, particularly about 0.2 bar.

In yet another aspect the invention provides for use in a suspendedceiling, a panel formed of a plastics material and having means for theflow of fluid medium therethrough, characterised in that the panel isshaped so that, in use, the fluid medium is in contact withsubstantially all of the lower surface of the panel.

Preferably the panel includes means to guide the flow of the fluidmedium through the panel from an inlet to an outlet.

Preferably the panel is formed of a material which has sufficientmechanical strength to support the weight of the panel and the fluidmedium without distortion. Most preferably the panel includes hook meansfor direct connection to hanger means.

BRIEF DESCRIPTION OF THE DRAWINGS:

In order that the invention may be well understood it will now bedescribed with reference to the accompanying diagrammatic drawings, inwhich:

FIG. 1 is a vertical section of one room;

FIG. 2 a plan view of one panel of the ceiling of FIG. 1;

FIGS. 3 and 4 show respectively a vertical section and a transversesection through the ceiling panel of FIG. 2;

FIGS. 5 and 6 shows respectively a vertical section and a transversesection through another ceiling panel of the invention; and

FIG. 7 is a partial elevation of two panels of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A room R contains a ceiling C suspended from the top surface T of theroom, e.g. an overlying floor or the roof of the building.

The ceiling C is made up of panels P located in the squares of a gridframe defined by T bars 2 which are connected to hanger rods 1 securedto the top surface T of the room. The space from the surface T to thetop of the ceiling 1 defines a building services space 6, which, asshown includes an inlet 3 in the outer wall 4 and contains a filter 7;at least one grid outlet 5 is present in the ceiling C to draw air fromthe duct 6 into the space of the room R. (The space 6 is an optionalfeature).

Each panel P comprises a lower wall 10 and an upper wall 11 which aresealed at their margins 12 to form a slab like structure. A fluidmedium, W, typically water, is present in the panel and enters via aninlet 13 and exits via an outlet 14. The water is supplied via pipes andpumps etc. not shown. It will be clear from the shape of the panel thatthe water W is in contact with all of the lower surface 10 so that aneffective heat transfer can take place between the heat in the air ofthe room R and the flowing water W. As shown in FIG. 1, the panels P areempty but as shown in the embodiments of FIG. 3 and in FIG. 5 the panelsmay have internal structures to guide the water flow so that it isspread evenly across the panels. Thus in the embodiment of FIGS. 3 and 4the upper wall 12 is formed with interior baffles 15 arranged in say aherringbone pattern as seen in plan view, to cause the water W to spreadevenly thinly over the lower surface 10. A finish may be applied to thepanels after molding, e.g. a paint layer especially of a textured paint10', as that will increase the surface area and avoid zones where thereis such a temperature difference that condensation can occur. In theembodiment of FIGS. 5 and 6 the inlet is set at one end of a pipe 16 thelonger side of which has perforations 17 to release small diameterparallel streams. As a result of these structures the heat transfer fromair to water is very efficient, and there is little or no heatdifference across the panel.

In the embodiment of FIG. 7, there are two panels P1, which at one end,the left hand end, as shown, have a projecting ledge or shoulder 18 andat the other a recess 19, dimensioned so that they can be abutted andpresent a continuous appearance. The top wall 11 has an end upper hook20 which engages the end of a hanger rod 1. As a result of thisarrangement the T bars 2 and the ceiling grid can be avoided, whichsaves a substantial proportion of the installation materials and timeotherwise required.

A panel of the invention preferably has a thickness from about 6 mm toabout 12 mm. The structure is made of material which has mechanicalstrength so that it can support its own weight and the weight of thewater and is shaped so that substantially all of the top and bottomsurfaces are exposed to air to provide heat transfer. Typically 80% ormore of the energy transfer is by heat radiation and 20% or less by heatconvention. Typically the water in a panel is at a pressure of 1 bar orless, preferably of about 0.2 bar, (which is much less than thepressurised water in say a floor or wall mounted central heatingsystem). In the case of a plastics panel of the invention the energytransfer ranges from about 60 to about 150 W/m². The air is relativelystill and not dried out.

The heat in the water W may be extracted for use (or storage) in asuitable medium. It may however be used to heat air, e.g. incoming airin the duct 6.

Because the invention works by extracting heat from a room withoutcausing extraction of the moisture at the same time, it provides anefficient method of controlling indoor climates without affecting thehumidity. Because there is no need for much air replacement it isparticularly suitable for sterile areas, e.g. hospital operatingtheatres. The apparatus is silent in use and environmentally acceptable.

The invention is not limited to the embodiment shown. For example thepanels can be moulded to the shape of the room and need not berectangular as seen in plan.

While this invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, the preferred embodiments of the invention as set forthherein, are intended to be illustrative, not limiting. Various changesmay be made without departing from the spirit and scope of the inventionas set forth herein and defined in the claims.

I claim:
 1. A building, comprising a room having a top surface, aceiling suspended by hanger means below said top surface, said ceilingincluding at least one panel through which a fluid medium flows, whereinsaid panel has a lower surface and said fluid medium is in contact withsaid lower surface to enable heat transfer to occur over substantiallyall of said lower surface, and further wherein a textured paint finishis present on said lower surface of said panel to increase the surfacearea thereof and to avoid zones thereon where there is such atemperature difference that condensation can occur.
 2. A buildingaccording to claim 1, wherein said lower surface of the panel iscontoured to increase the surface area thereof.
 3. A building accordingto claim 1, wherein the panel is received in a grid frame formed byT-bars to which said hanger means are connected.
 4. A building accordingto claim 1, wherein hook means are present on the panel, said hook meansbeing connected to the hanger means to suspend the panel directly fromthe hanger means.
 5. A building according to claim 1, wherein saidceiling constitutes a lower wall of a building services duct.
 6. Abuilding according to claim 5, including an inlet for enabling incomingfresh air to enter the duct, wherein the ceiling panel is arranged totransfer heat from an upper surface of the panel to said fresh air.
 7. Amethod of cooling a room in a building, the room including a ceilingsuspended by hanger means below a top surface of the room, the ceilinghaving panels through which a fluid medium is passed, a textured paintfinish being present on a lower surface of the panels, said methodcomprising the step of causing the fluid medium to contact the lowersurface of the panels for cooling the room and providing substantiallyno temperature difference across the lower surface of the panels so thatcondensation thereon is avoided.
 8. A method according to claim 7,further including passing the fluid medium through said panels under apressure of less than about 1 bar.
 9. A method according to claim 8,further including passing the fluid medium through said panels at apressure of about 0.2 bar.
 10. A panel for use in a suspended ceiling,said panel being formed of a plastic material and comprising means forenabling a fluid medium to flow therethrough, said panel having a shapewhich enables the fluid medium to contact a lower surface of the panel,said panel further including a textured paint finish on the lowersurface of the panel to increase surface area thereof and avoid zoneswhere there is such a temperature difference that condensation canoccur.
 11. A panel according to claim 10, further including hook meansfor enabling direct connection of said panel to hanger means forsuspending said panel.